Long ago the primary motivations with humans was survival. If you could help someone survive, you could motivate them to do just about anything.

More recent the method of motivating people, mostly employees, was carrots & sticks.

Now, Daniel Pink explains in his book Drive, to motivate or influence the actions of more and more people, you have to find something else. This is not universal for everyone, at this point, but the more a task requires creativity, the less extra money will cause better results.